discover/boot: Download resources in parallel

Now that we can download asynchronously, we can download boot resources
in parallel. This also means we don't need a state machine; we're either
not done (loads are still pending) or done.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

diff --git a/discover/boot.c b/discover/boot.c
index 2f381a7d0e069619120ccc234a4f2f33ba1effae..ca088dc7673cc58293b0d93062153bd684031e1e 100644 (file)
--- a/discover/boot.c
+++ b/discover/boot.c
@@ -27,25 +27,13 @@ enum {
        BOOT_HOOK_EXIT_UPDATE   = 2,
 };
 
        BOOT_HOOK_EXIT_UPDATE   = 2,
 };
 

-enum boot_process_state {
-       BOOT_STATE_INITIAL,
-       BOOT_STATE_IMAGE_LOADING,
-       BOOT_STATE_INITRD_LOADING,
-       BOOT_STATE_DTB_LOADING,
-       BOOT_STATE_FINISH,
-       BOOT_STATE_UNKNOWN,
-};
-
-

 struct boot_task {
        struct load_url_result *image;
        struct load_url_result *initrd;
        struct load_url_result *dtb;
        const char *args;
 struct boot_task {
        struct load_url_result *image;
        struct load_url_result *initrd;
        struct load_url_result *dtb;
        const char *args;

-       struct pb_url *image_url, *initrd_url, *dtb_url;

        boot_status_fn status_fn;
        void *status_arg;
        boot_status_fn status_fn;
        void *status_arg;

-       enum boot_process_state state;

        bool dry_run;
 };
 
        bool dry_run;
 };
 


@@ -288,6 +276,25 @@ static void run_boot_hooks(struct boot_task *task)
        free(hooks);
 }
 
        free(hooks);
 }
 

+static bool load_pending(struct load_url_result *result)
+{
+       return result && result->status == LOAD_ASYNC;
+}
+
+static int check_load(struct boot_task *task, const char *name,
+               struct load_url_result *result)
+{
+       if (!result)
+               return 0;
+       if (result->status != LOAD_ERROR)
+               return 0;
+
+       update_status(task->status_fn, task->status_arg,
+                       BOOT_STATUS_ERROR,
+                       "Couldn't load %s", name);
+       return -1;
+}
+

 static void cleanup_load(struct load_url_result *result)
 {
        if (!result)
 static void cleanup_load(struct load_url_result *result)
 {
        if (!result)


@@ -299,90 +306,21 @@ static void cleanup_load(struct load_url_result *result)
        unlink(result->local);
 }
 
        unlink(result->local);
 }
 

-static void boot_process(struct load_url_result *result, void *data)
+static void boot_process(struct load_url_result *result __attribute__((unused)),
+               void *data)

 {
        struct boot_task *task = data;
        int rc = -1;
 
 {
        struct boot_task *task = data;
        int rc = -1;
 

-       if (task->state == BOOT_STATE_INITIAL) {
-               update_status(task->status_fn, task->status_arg,
-                               BOOT_STATUS_INFO, "loading kernel");
-               task->image = load_url_async(task, task->image_url,
-                                               boot_process, task);
-               if (!task->image) {
-                       update_status(task->status_fn, task->status_arg,
-                                       BOOT_STATUS_ERROR,
-                                       "Couldn't load kernel image");
-                       goto no_load;
-               }
-               task->state = BOOT_STATE_IMAGE_LOADING;
+       if (load_pending(task->image) ||
+                       load_pending(task->initrd) ||
+                       load_pending(task->dtb))

                return;
                return;

-       }

 
 

-       if (task->state == BOOT_STATE_IMAGE_LOADING) {
-               if (result->status == LOAD_ERROR) {
-                       update_status(task->status_fn, task->status_arg,
-                                       BOOT_STATUS_ERROR,
-                                       "Error loading kernel image");
-                       goto no_load;
-               }
-               task->state = BOOT_STATE_INITRD_LOADING;
-
-               if (task->initrd_url) {
-                       update_status(task->status_fn, task->status_arg,
-                                       BOOT_STATUS_INFO, "loading initrd");
-                       task->initrd = load_url_async(task, task->initrd_url,
-                                                       boot_process, task);
-                       if (!task->initrd) {
-                               update_status(task->status_fn, task->status_arg,
-                                               BOOT_STATUS_ERROR,
-                                               "Couldn't load initrd image");
-                               goto no_load;
-                       }
-                       return;
-               }
-       }
-
-       if (task->state == BOOT_STATE_INITRD_LOADING) {
-               if (result->status) {
-                       update_status(task->status_fn, task->status_arg,
-                                       BOOT_STATUS_ERROR,
-                                       "Error loading initrd");
-                       goto no_load;
-               }
-               task->state = BOOT_STATE_DTB_LOADING;
-
-               if (task->dtb_url) {
-                       update_status(task->status_fn, task->status_arg,
-                                       BOOT_STATUS_INFO,
-                                       "loading device tree");
-                       task->dtb = load_url_async(task, task->dtb_url,
-                                                       boot_process, task);
-                       if (!task->dtb) {
-                               update_status(task->status_fn, task->status_arg,
-                                               BOOT_STATUS_ERROR,
-                                               "Couldn't load device tree");
-                               goto no_load;
-                       }
-                       return;
-               }
-       }
-
-       if (task->state == BOOT_STATE_DTB_LOADING) {
-               if (result->status) {
-                       update_status(task->status_fn, task->status_arg,
-                                       BOOT_STATUS_ERROR,
-                                       "Error loading dtb");
-                       goto no_load;
-               }
-               task->state = BOOT_STATE_FINISH;
-       }
-
-
-       if (task->state != BOOT_STATE_FINISH) {
-               task->state = BOOT_STATE_UNKNOWN;
-               return;
-       }
+       if (check_load(task, "kernel image", task->image) ||
+                       check_load(task, "initrd", task->initrd) ||
+                       check_load(task, "dtb", task->dtb))
+               goto no_load;

 
        run_boot_hooks(task);
 
 
        run_boot_hooks(task);
 


@@ -416,12 +354,29 @@ no_load:
        talloc_free(task);
 }
 
        talloc_free(task);
 }
 

+static int start_url_load(struct boot_task *task, const char *name,
+               struct pb_url *url, struct load_url_result **result)
+{
+       if (!url)
+               return 0;
+
+       *result = load_url_async(task, url, boot_process, task);
+       if (!*result) {
+               update_status(task->status_fn, task->status_arg,
+                               BOOT_STATUS_ERROR,
+                               "Error loading %s", name);
+               return -1;
+       }
+       return 0;
+}
+

 int boot(void *ctx, struct discover_boot_option *opt, struct boot_command *cmd,
                int dry_run, boot_status_fn status_fn, void *status_arg)
 {
 int boot(void *ctx, struct discover_boot_option *opt, struct boot_command *cmd,
                int dry_run, boot_status_fn status_fn, void *status_arg)
 {

+       struct pb_url *image = NULL, *initrd = NULL, *dtb = NULL;

        struct boot_task *boot_task;
        struct boot_task *boot_task;

-       struct pb_url *image = NULL;

        const char *boot_desc;
        const char *boot_desc;

+       int rc;

 
        if (opt && opt->option->name)
                boot_desc = opt->option->name;
 
        if (opt && opt->option->name)
                boot_desc = opt->option->name;


@@ -444,25 +399,23 @@ int boot(void *ctx, struct discover_boot_option *opt, struct boot_command *cmd,
                return -1;
        }
 
                return -1;
        }
 

-       boot_task = talloc_zero(ctx, struct boot_task);
-       boot_task->image_url = image;
-       boot_task->dry_run = dry_run;
-       boot_task->status_fn = status_fn;
-       boot_task->status_arg = status_arg;
-       boot_task->state = BOOT_STATE_INITIAL;
-

        if (cmd && cmd->initrd_file) {
        if (cmd && cmd->initrd_file) {

-               boot_task->initrd_url = pb_url_parse(opt, cmd->initrd_file);
+               initrd = pb_url_parse(opt, cmd->initrd_file);

        } else if (opt && opt->initrd) {
        } else if (opt && opt->initrd) {

-               boot_task->initrd_url = opt->initrd->url;
+               initrd = opt->initrd->url;

        }
 
        if (cmd && cmd->dtb_file) {
        }
 
        if (cmd && cmd->dtb_file) {

-               boot_task->dtb_url = pb_url_parse(opt, cmd->dtb_file);
+               dtb = pb_url_parse(opt, cmd->dtb_file);

        } else if (opt && opt->dtb) {
        } else if (opt && opt->dtb) {

-               boot_task->dtb_url = opt->dtb->url;
+               dtb = opt->dtb->url;

        }
 
        }
 

+       boot_task = talloc_zero(ctx, struct boot_task);
+       boot_task->dry_run = dry_run;
+       boot_task->status_fn = status_fn;
+       boot_task->status_arg = status_arg;
+

        if (cmd && cmd->boot_args) {
                boot_task->args = talloc_strdup(boot_task, cmd->boot_args);
        } else if (opt && opt->option->boot_args) {
        if (cmd && cmd->boot_args) {
                boot_task->args = talloc_strdup(boot_task, cmd->boot_args);
        } else if (opt && opt->option->boot_args) {


@@ -472,7 +425,14 @@ int boot(void *ctx, struct discover_boot_option *opt, struct boot_command *cmd,
                boot_task->args = NULL;
        }
 
                boot_task->args = NULL;
        }
 

-       boot_process(NULL, boot_task);
+       /* start async loads for boot resources */
+       rc = start_url_load(boot_task, "kernel image", image, &boot_task->image)
+         || start_url_load(boot_task, "initrd", initrd, &boot_task->initrd)
+         || start_url_load(boot_task, "dtb", dtb, &boot_task->dtb);

 
 

-       return 0;
+       /* If all URLs are local, we may be done. */
+       if (!rc)
+               boot_process(NULL, boot_task);
+
+       return rc;

 }
 }